PH67399: ABN=5C6-00E50001,U=XXXXXXXX,C=MQ900.930.DMC -CSQILOC2,M=CSQGFRCV,LOC=CSQILPLM.CSQILOC2+OFFSET

APAR status

• Closed as program error.

Error description

• The following abend occurred:
  ABN=5C6-00E50001,U=XXXXXXXX,C=MQ900.930.DMC
  -CSQILOC2,M=CSQGFRCV,LOC=CSQILPLM.CSQILOC2+OFFSET The abend
  occurred in CSQILOC2 when trying to latch a CLXQ synonym hash
  chain latch. The problem is that the thread already holds a
  different CLXQ synonym hash chain latch from CSQMCTQI. CSQMCTQI
  is retrying a pending deletion of a DEFCLXQ(CHANNEL) probably
  because QMGR hadn't communicated with another QMGR in the
  cluster for a long time. CONFIGEV is ENABLED so as part of the
  deletion of the DEFCLXQ(CHANNEL) dynamic queue, CSQMCLS2 puts a
  config event message to the SYSTEM.ADMIN.CONFIG.EVENT. In this
  specific case, the SYSTEM.ADMIN.CONFIG.EVENT is an alias queue
  pointing to another queue that is a clustered queue on another
  queue manager, and thus the putting process must open the
  transmission queue to that QMGR. This requires getting a CLXQ
  synonym hash chain latch, which abends because the pending
  deletion logic CSQMCTQI already holds a synonym hash chain latch
  for the queue associated with the QMGR being deleted.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 3 Modification 0 and Release 4       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: When a permanent dynamic queue defined  *
  *                      by DEFCLXQ(CHANNEL) is being deleted    *
  *                      during the removal of a queue manager   *
  *                      from a cluster, the task abends         *
  *                      5C6-00E50001 when generating            *
  *                      configuration events. This can occur    *
  *                      while the system generates a            *
  *                      configuration event message for the     *
  *                      deletion of the queue and attempts to   *
  *                      put that event onto a remote clustered  *
  *                      queue.                                  *
  ****************************************************************
  The code which handles the deletion of permanent dynamic queues
  after the removal of a queue manager from a cluster, holds a
  latch to the hash chain associated with cluster transmission
  queues. During the deletion, we also process the configuration
  event if these are enabled. When putting the event to a
  configuration event queue that is remote within the cluster, the
  transmission queue must also be opened, which requires getting
  hold of the same latch, leading to the ABEND.
  

Problem conclusion

• The code has been changed to avoid generating a configuration
  event when creating and deleting a permanent dynamic cluster
  transmit queue defined by DEFCLXQ(CHANNEL).
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UO07846 UO07847

Modules/Macros

• CSQMCLS2 CSQMCTQI CSQMOPNI CSQMQMR2 CSQMQMR3
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels